The automated radiosynthesis of [18F]FP-TZTP.

[(18)F]FP-TZTP (3-(3-(3-[(18)F]fluoropropylthio)-1,2,5-thiadiazol-4-yl)-1,2,5,6-tetrahydro-1-methylpyridine) is a muscarinic ligand that displays in vivo selectivity for the M2 subtype. We have developed a one-step radiosynthesis of [(18)F]FP-TZTP that can be conducted with an automated synthesis unit. A number of hardware and software modifications to a Nuclear Interface C-11 Methylation System provided the equipment for the automated radiosynthesis. The manual synthesis produced [(18)F]FP-TZTP in a radiochemical yield of 23.4% +/- 4.3% (EOS, n = 69) with a specific activity of 4377 +/- 2011 mCi/micromol (EOB, n = 100). The automated synthesis unit provided the product in a radiochemical yield of 18.8% +/- 2.4% (EOS, n = 25) with a specific activity of 4112 +/- 2572 mCi/micromol (EOB, n = 25).